第二题:
public class Person {
private String name;
public Person(){
}
public Person(String name){
super();
this.name = name;
}
public String getName(){
return this.name;
}
}
public class Dog {
private String name;
public Dog(){
}
public Dog(String name){
super();
this.name = name;
}
public String getName(){
return this.name;
}
}
import java.util.Map;
import java.util.HashMap;
import java.util.Map.Entry;
import java.util.List;
import java.util.ArrayList;
public class HashDemo {
public static void main(String[] args) {
Map<Person,Dog> hashMap = new HashMap<Person,Dog>();
List<Person> list = new ArrayList<Person>();
Person person_obj = null;
for(int i=0;i<100;i++){
person_obj = new Person("person_name" + i);
hashMap.put(person_obj, new Dog("dog_name" + i));
list.add(person_obj);
}
//Keyset
for(Person p : hashMap.keySet()){
System.out.println(p.getName() + "---" + hashMap.get(p).getName());
}
//EntrySet
for (Entry<Person, Dog> entry : hashMap.entrySet()) {
System.out.println(entry.getKey().getName() + "---" + entry.getValue().getName());
}
for(Person pl : list){
hashMap.remove(pl);
}
System.out.println("------------");
System.out.println(hashMap.size());
}
}本文出自 “森林敏” 博客,请务必保留此出处http://senlinmin.blog.51cto.com/6400386/1774754
原文地址:http://senlinmin.blog.51cto.com/6400386/1774754